I can answer that. If the seller is a person who is dumb enough to think that these are 50s, even with access to the internet which would in every way show him otherwise, then he is also the type to be dumb enough to get angry over someone trying to share knowledge with him. Some people will get angry over nothing, or they think they know it all and are never wrong. No one likes to be wrong, but some people cannot take it. I cannot fathom the mindset of people like that, but I have seen them. Was the guy in his 20s or 30s, because I would think if he was any older he would be able to immediately know that they are not 50s?
Over the years I've messaged quite a few eBay sellers in an attempt to help them correct their listings. Many are thankful for the information and corrected their listing and less than handful were real jerks. One was an occasional member here I found out later, and another one is a well known butcher of Schwinns that built fake Cruiser 5's. When you list a chrome part and say it's NOS you have to make sure it's not all marked up from a wrench or from being previously mounted. If it was a part taken off a somewhat nice or new bike, then it's called a new take off, not NOS.